The reason for TapaTalk is that on my phone, the regular GG webpage loads as a very small image. To read posts and navigate I have to constantly magnify the pages in order to read content.
TapaTalk takes the GG Website and converts the contents into a very readable format that I can easily navigate without constantly magnifying and scrolling through the various posts. Also uploading images and documents is easily accompished with the TapaTalk app.
That said, it's not perfect. Sometimes TapaTalk won't let me upload pics and it's very frustrating. However, once a problem is reported to TapaTalk tech support, they are very responsive. The last time this uploading problem happened, they fixed my problem within a few hours and e-mailed me back to check up if they had indeed fixed my issues.
I prefer TapaTalk on my I-Phone because my eyes are not what they used to be -- and it makes it a lot more convenient to browse and post on the GG.