Lenovo implemented in some of their phones unfortunate extension (breaking Android spec) that prevents apps starting by default. They have also power saving mode that kills apps running in background. You have to explicitly enable auto start for my app and enable app to work in background if you have to use it. Sorry for inconvenience.
Open Settings/Background app management:
Make sure that our app is UNCHECKED. It means it WILL BE STARTED on startup and well as it will NOT BE KILLED when screen is closed.
There is also one more function that may cause our app is not working well.
Go to Settings/Applications
Open our app (Twitter is just as example) and make sure that Restrict to launch checkbox is UNCHECKED.
Please contact us if you still experience problems with the app.