[Galaxy Tab 2 Q&A, Help & Troubleshooting] TheTecXpert:
When you install drivers for devices such as phones,tablets etc. Just remember to connect the device to the pc 2 times for the first 2 series of drivers..

First, connect said device to pc while it is powered on with home screen unlocked.. This will install the first few initial drivers that it needs in order to be able to access the devices internal storage and external sd card storage.

Once this is done, unplug usb cable from the device end (not usb/pc end) and turn the device off completely..

Once device is off, reinsert the cable to the device and that should install the second series of drivers on the pc. Once all drivers are installed and device is recognized by adb and fastboot, you should be able to safely proceed..

One thing i noticed in your post also was that adb is recognized. But not fastboot.. I dont mean to sound rude in any way(so please take this question that im about to ask you as a genuine question without any offense intended as I just want to help you fix your problem), so umm, are you aware that adb and fastboot are both connected to the PC in 2 different ways? In case you aren't / weren't ill explain to you exactly what i mean.

1. To connect via adb :

1a. Turn off device

1b. Hold vol up key and plug usb cable in to phone/pc (while holding vol up). This will cause the phone led to light up (to whatever color your phone led is programmed for) usually red or green or orange (devices can differ from others).

Then on your pc using a program such as minimal adb and fastboot tool, run the program as administrator if you have UAC enabled on your pc. If not you're already running as administrator so just double click to run the program

Now go ahead and type adb devices. And if all is well. Your device will be shown.

2. Now, for "FASTBOOT" to detect your device (depending on device).

You can do this in 2 different ways.

2a. If your device is still in adb mode and connected to your pc with the program still running, then in the command shell (text field) you can simply type the following command..

"Adb reboot fastboot" without quotes..

This should reboot your device in to "fastboot" mode if successful.

To check that you are connected in fastboot mode type "fastboot devices" without the quotes. And if all is well, you should see your connected device.

Also note that when in fastboot mode, many devices LED notification light will be a solid blue color. Also your pc will in most cases attempt to install the fastboot drivers of your device if they do not already exist.. If it does that is a firm indicator that you're device is in fastboot mode..

I hope this long explanation was helpful mate. And i apologise if it wasnt useful to you. Just trying to be helpful :).

Let me know if theres anything i can help you with. And take care

---------- Post added at 03:26 PM ---------- Previous post was at 03:24 PM ----------

If im correct and my memory serves me well,

Then I'm pretty confident that a flash counter counts the amount of times that a device is flashed with custom roms/kernels etc..

Usually you will see this information within a devices "hidden service/system menu and device info section"

---------- Post added at 03:48 PM ---------- Previous post was at 03:26 PM ----------

Instead of downloading from playstore, in the past on my old samsung devices I'm pretty sure that getting rid of the triangle during boot was fixed by reflashing a stock kernel over a custom rom on samsung devices, or there was a flashable patch for it via recovery or something like that, i cant remember exactly how i did it since it was a few years ago and i havent had a samsung phone in years. I had an s2 back then when they first came out. It must be the S series of samsung phones that have this issue still or something hey?

I have a samsung galaxy tab 2 10.1 but that never had triangle issue. So its only with the phone models im guessing. And obviously different architecture aswell, i think. Bit rusty with samsung im afraid :p.

But anyway. I'm pretty sure theres a fix or flashable patch or something thst gets rid of it without the extra app running on your device. Or maybe, look for a zip version of the triangle away apk file on the web, or download it as an apk file and zip it. Then transfer the file to root of sdcard or jnternal memory. And flash it via custom recovery?? If it works then atleast itll run as a core system service during boot sequence instead of having it as an add-on application..

Just athought :p