Hi Felipe Oliveira,
Please tell me the platform you are using and your operation step.
When you use the flashloader as the bootloader, you need to follow this step:
1. make sure you already install Python in your PC, you can download it from : www.pyhon.org
2. complier flashloader at first
3. complier flashloader_loader, and download it to your flash.

4, use KinetisFlashTool to download the .bin file in NXP_Kinetis_Bootloader_2_0_0\apps\led_demo\MK02F12810\iar\binaries\led_demo_tower_a000
Before you test led_demo_tower_a000, I suggest you test led_demo_tower_0000 on your board at first, whether it can work without the bootloader.
5. After download the app file with bootloader, then reset the board, wait a moment, check the app function.
Please try it again on your side.
Any question, please let me know!
Have a great day,
Kerry
-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------