Function Inspector special offer!

Here's some good news: Function Inspector PRO will be available for only 0.50 € starting now and ending this sunday!

You can buy it from Google Play.

But wait, you can also get it for free! All you need to do is to share this picture publicly on Facebook and fill out the following form. This also ends on Sunday! And: please allow the Unlock Code distribution to take some time, I need to do it manually.

Attention: this offer is closed by now.

Function Inspector Unlock - Get code for free!

One thing I always wanted to do with Function Inspector PRO is to give it away for free - not in general, but at least to some. This has always been difficult as, to my knowledge, no Android market offers this functionality. The only alternative so far was to send the PRO APK directly to the user which means that the user will not receive any updates and developers give up any control of how many people use this app.
That is why I was glad when I first heard about BoomCodes. The idea is simple: Developers can generate promotion codes, issue it to their users who will then be able to unlock the PRO features. Once the features are synchronized, the app works just like the PRO version; updates will be issued via the market.

So, I published Function Inspector Unlock which will do exactly that! I don't really know yet what I want to do with this in the future, but I could imagine using it for promotion on my Facebook and Google Plus page, rewarding beta testers and translators or offering alternative payment methods.

For now, I will just give it away for free!

The first 5 folks that enter their Email address in the form below will receive a free promotion code for free that will allow them to unlock PRO features at Function Inspector Unlock!

The 5 free codes have been distributed! Thanks to all participants.

Function Inspector 4.0 Release

So now it is done, I finally released Function Inspector 4.0 to Google Play. I don't want to talk a lot of the changes because I already have. My special thanks goes to the beta testers!

Here are to pictures that display the main visual changes: New design, new UI and, finally, a "Help" menu ;)

Function Inspector 4.0 Beta Testing

With this version of Function Inspector 4.0 Beta you will
be able to return directly to this post as well as switch to
the PRO version (must be redone after restart).

I have made some progress after my last post. I have redone the design and User Interface, fixed several bugs and added a Help dialog. More importantly though, I have reorganized the existing code and changed a lot under the hood. There is basically not much that has not changed ;)

Also, I have had some problems in the past with issues that occur only on certain devices, on certain Android versions and so on. It is not that easy for devolopers to make sure that those problems won't occur

That is why I need you to test the Beta version of Function Inspector 4.0! If you have some time and are interested in the new features of Function Inspector, you would do me a great favour if you would install this version on your device and report any issued you may have with this. In the app, you will easily get back to this post in order to receive newer versions or track issues.

This version contains all the features that will be part of Function Inspector 4.0 except for some design elements and translations. If Beta Testing goes well, I will hopefully be able to release this in a few days ;)

Thanks in advance!

Download Current Version

Function Inspector 4.0 Beta 1 (9-11-2012)
Function Inspector 4.0 Beta 2 (9-13-2012) (Bug fixes, Color Scheme, New Design Elements)

Issue tracker

I'm back!

It has been some time since I last posted here or published an update to one of my Android Apps. This has a lot to do with my studies in Software Engineering as well as a new job I got.

But now, I'm back to continue my personal projects. Of course, the main focus will be on Function Inspector as it is by far the most successful and most complex project for now. Function Inspector LITE, for example, has been downloaded almost 80,000 times...

Yesterday, I published an update fixing the issue you can see on the screenshot I got from a user. This occurred on Android Jelly Bean for the first time, I'm sorry for any inconveniences ;)

So there is a lot to do. This is my To-Do-List for Function Inspector:

• Refactoring: Most of the code is older than a year, and I'm pretty sure my programming skills have improved since then ;)
• Performance improvements and bug fixes: Some parts of the app could probably be optimized.
• Design: The design of Function Inspector seems kind of outdated and does not fit into the new Android 4.x design. For example, I could get rid of the menu button.
• Tablet support: The Function Inspector UI works fine on tablets, but it could certainly be optimized.
• New functionality? Here, I'm hoping for some user suggestions.
• Marketing: As satisfying as download numbers are, there are many people out there that could probably need this app.

So as you can see, it won't get boring!

Function Inspector PRO featured in ComputerBILD

I've got exciting news for all you German users out there:
The German magazine ComputerBILD is featuring Function Inspector PRO on todays issue. It is Germany's largest Computer Magazine.
Here's the proof:

Function Inspector Promotion Video

I've published a new video that shows of some of the features Function Inspector has to offer. Hope you enjoy ;)

Function Inspector 3.2

I know, it has been months. But I finally finished an update which brings a lot of features that were requested by my users!

So, here are the changes:

You can now calculate the definite
integral right from Function Inspector

• Definite integral: I integrated the functionality that you know from my other App IntegralCalc. It can be accessed from the menu next to each function.
• Tangent equation: In slope mode, you can now display the equations of the tangents that are currently displayed.
• Improved table: It now looks a lot better and you can choose what three functions you want to use (as opposed to taking the first three).
• Factor out: In the settings or by longpressing the coordinate system, you can now factor out PI, e and DEG from the lables of each of the coordinate axes. This means that you can choose, whether the root of sin(x) is lables (3.1214|0), (1π|0) or (180°|0).

Function Inspector & IntegralCalc updates!

New Splash Screen for
Function Inspector

One thing that I got a lot of complaints about was the very limited amout of functions that one could use in an equation in Function Inspector. Today's update adresses this problem! IntegralCalc has been updated as well, changing the same thing.

Those are the changes of Function Inspector 3.1:

• More functions like abs(), asin(), sinh(), asinh(), ... (Also applies to IntegralCalc 2.5)
• A Splash Screen is now shown while the app is loading anyway
• New Ad Network in LITE version (also for IntegralCalc 2.5) in order to hopefully make more money xD

The second page of Function Inspector's
new keyboard with new functions and an
info-button

Also, I increased the price of Function Inspector PRO from 0.99 € to 1.49 € which I think is still a price that the app is worth ;)
I hope you like this update!

Function Inspector promotion video

Hey,
today I just took my camera, a white board, my freaking old PC and this awful peace of software called "Movie Maker" and made a promotion video for Function Inspector.
So, from that short description, you can guess that the result is not the most professional that you could think of, but it sure is better than nothing! So let me know what you think!

Function Inspector Facebook Page

Today I want to invite you to visit my Function Inspector Facebook page and like it!

I created in this page in order to have even closer contact to my users. They can now use this page to begin a discussion as well as to recommend the app to friends!

I'm excited to see how many Likes I can gather! So now it's your turn:

Function Inspector 3.0

Version 3.0 comes with a new keyboard
as well as the possibility to enter
an unlimited number of functions.

I am finally publishing the probably largest upgrade to Function Inspector that was ever released.

Here are the major changes:

• Unlimited number of equations (PRO only)
• Redesigned keyboard: The new keyboard looks better and adds new buttons like the "down" button which you can use to select the input field below
• Three parameters: In addition to parameter 'a', you can also integrate 'b' and 'c' to your equation (PRO only)
• Display discontinuities (PRO only)
• Redesigned menu layout: The last button in the menu bar can know be used to switch the mode while the screenshot dialog has been moved to the menu that appears when you press the menu-button
• Better performance: Drawing is now done in the background. So, even if you draw many functions on slow devices, you can, for example, still move the coordinate system while the app is redrawing the graphs
• Much more: This update also includes several bug fixes and minor improvements

Unfortunately, I had to drop the Chinese translation in this update, because it just wasn't up-to-date anymore...

All in all, I think this is a major update. Therefore, I'm really excited to receive your feedback!!!

Function Inspector one of "Best Mathematical Graph Plotters"

I just found an article from addictivetips.com which compares Function Inspector with 2 more Android graph plotters, AndroPlotter and Grapher.

This is what it says about Function Inspector:

Function Inspector Lite has a few features in addition to those in the other two. However, most of these can only be used to the full in the paid (PRO) version of the application.The app sports only the most essential functions, can plot only one function at a time in the free and up to a maximum of 3 in the paid version. Still, features like the ability to display roots and other special points of plotted functions and three modes of interaction with the graph window namely panning, tracing and slope (PRO version only) modes do indeed make it the “most advanced graphing calculator available on the Market”. Another feature that catches the eye is the real-time update of the graph with every change made in the entered function.

Since it was compared to two free apps I understand the critique that many features are only available in the PRO version. And the fact that the app does not offer a lot of functions will be an incentive for future versions.
All in all, I think this is a pretty good review! Which can be proven by the bottom line of the article:

If you’re all for functionality and are ready to spend some cash, Function Inspector is the way to go.

So far, this was the first review on my app. Please comment if you found more ;)

But for know, I will focus on version 3.0 which will probably launch in 2 weeks!

Function Inspector 2.8

tan(x) and 1/x: Function Inspector 2.8
recognizes asymptotes and eliminates
vertical lines

I just published an update to Function Inspector which includes the following changes:

• Recognition of Asymptotes: functions like tan(x) or 1/x are no longer drawn with a vertical line
• No more haptic feedback for the keyboard: A user complained about it and I decided that it is unnecessary. If you found this feature useful, please let me know!
• Background work: I improved the existing code which should not affect the look and feel that you are used to. If it does, please let me know!

As you can see, Function Inspector is going towards its 3.0 release which will be a major upgrade as I am planning to make some changes to the UI as well as to improve the functionality.

But that's it for now, I hope you'll enjoy the update ;)

Function Inspector 2.7.1

This is a very minor but convenient update:
When the function input menu is opened, the first empty input box is focussed automatically, so you don't have to click in it!

Other than that I've been working on improving the existing code which is hard work that you don't notice, but it might speed up future updates ;)

Function Inspector 2.7

On Friday, I published the new version of Function Inspector which has the following changes:

• Improved look: As you can see on th picture, I turned on anti-aliasing which makes numbers look a lot better
• Extra folder for screenshots: Screenshots are no longer saved in the root directory of the SD card but in the folder you specify in the settings
• Improved buy dialog: Users of the LITE version can now choose from which market they want to buy the PRO version. For now, the AndroidPIT App Center is listed beside Android Market. I chose to let the user choose their market in order to let competition between the markets do some work ;)
• Bug Fixes: For example that "set a" works all the time, even if it is bigger than the maximum a.

As you can see, the changes are not that significant considering that it took about two weeks. This has to do with stress at school which will hopefully end with easter holidays when I'm going towards graduation ;)

Also, I want to thank everyone that provided feedback. During the last days, I received lots of feedback through my survey or through email which has been very useful!

Function Inspector on Motorola Xoom

Thanks to Alex, I got some pictures of the Motorola Xoom running Function Inspector PRO.
As you can see, it is not optimized to run on screens of that size. Since this has a screen resolution of 1280 by 800, a completely new approach of layout is required. This will be a long-term goal of further development, but as I do not own a tablet, this will be complicated.

Function Inspector 2.6

Function Inspector 2.6 brings some major changes to the to the LITE version: First, you are now able to enter up to three functions, as in the PRO version. Furthermore, you can now test Function Inspector PRO in a Trial: You will once have the full functionality of Function Inspector PRO until you restart!
The only drawback is that I disabled the light color scheme in FI LITE ;)

Also, Function Inspector is now translated into Spanish! Thank you, Mario ;)

A new feature in FI PRO is that you can now set a different scale for the x and y dimension. This needs to be enabled in the settings.

I hope you enjoy the updates ;)

Andspot Market: USD 1.25 for Function Inspector PRO

I just uploaded Sudoku Solver, IntegralCalc and Function Inspector LITE/PRO onto the Andspot Market.
This is a new Android app market that adds social features to the usual market experience. Here is a quote from the email they sent me:

All users can:

• Directly Message you for support and feedback
• Build a Community around your app
• Find your app through their Friend
• Share your app on Facebook and Twitter
• Purchase or donate money using Paypal
• much more (see andspot.com/users.cfm)

Also, there is a very important difference to the Android Market: The developer can (at least for now) keep 80% of the sale price! Therefore, I can offer Function Inspector PRO for USD 1.25 (EUR 0.89) instead of USD 1.49 (EUR 0.99) in the Android Market!

Major updates for IntegralCalc & Function Inspector

I just released IntegralCalc 2.0 and Function Inspector 2.5. The main change in those updates is that both apps are now linked!

Function Inspector 2.5:

• IntegralCalc link
• save/open Functions (PRO only)
• Trackball support in Tracing/Slope mode
• now plots functions immediately

IntegralCalc 2.0:

• Function Inspector Link