Force 4G LTE Only will help to change network to 4G/3G/2G and stay in chosen network. it can opens a secret menu where advanced network configurations can be selected.

Features :

*Change network to "LTE Only or 4G Only" mode
*Lock to any particular Network Signal like 4G(LTE)/3G/2G only
*Phone will disconnect less often leading to faster internet speed
*Enable VoLTE on supported devices(enables direct call over 4G network)
*Advanced network statistics
*Change network parameters
*Support Dual SIM

No more auto switch betwen 4G/3G.
If you have free 4G data transfer, just set up your network for only LTE.
Force 4G LTE Only not working on every phone. Some phone brands block opportunity to force switch network.
Pleas don't rate down this app if is not working on your phone.