I have been using tango eye since last 3 years with great results in terms of ROI. The team has always supported me if something went wrong or we are facing any technical issues. It's my go-to solution provider when it comes to building custom solutions like Point Of Sale (POS) applications/ web stores etc. Nothing much as such but they also support other platforms too so you can check their portfolio before deciding about hiring them. They do amazing work. We use TangeloEye POS application where orders from mobile apps get stored locally and then synced across multiple locations via app links which makes things very easy & transparent.