I thought to write up a general troubleshooting guide. Before you post about your problem or issue maybe this guide can help you solve the problem. At least you have taken these steps and can provide the results of your troubleshooting as you post about the issue.
If you are encountering Battery issues, Apps closing/crashing abnormally, sluggish performance, Unresponsiveness, etc.. these steps may or may not solve the issue but you should do these just to make sure the basics are covered.
I hope this helps
I am loyal to the brand and have had Galaxy S2, S3, Note 3, Note 4 Edge, Edge + S6 and S7 Edge now. I had never had a cell to present so many problems of coverage. I can hardly make calls. T-Mobile says it is the simcard. Problems continue to change and not to do.