If you own a Huawei phone, please check this tutorial. For Samsung, this tutorial. For other models running Android, this tutorial.
Newer versions of Android starting version 5, have power saving features that are enabled by default and cause VoIP apps like Toky, to be closed automatically after a few minutes the app was opened.
To prevent this from happening, please follow the next steps:
Go to the Settings page of your Android phone, and click on Battery
In the Battery section, click on Detail
Finally, find Toky and turn power saving off
Not all Android versions have this option in the same place. If you can't find it in yours, please contact our support team.