Apps do not help charging the phone faster - your smartphone should support it in the first place.
The fast charging depends on your hardware. If your smartphone supports fast charging (Qualcomm quick charge or Dash charge) - it should be mentioned with the specifications on your phone.
If you do not observe fast charging or quick charging mentioned on your smartphone specsheet (or the box), - then you cannot charge your smartphone faster than the normal rate.
Now a days everyone knows this, Instead of using apps, methods like switching phone off while charging if calls and alarms doesn’t matter or useing airplane mode which speeds up charging drastically.
Please don’t take me wrong, your app UI is good try to create some content/service based apps.