We have been using Simplicity for about two years now across multiple departments within our organisation - we've deployed four apps so far (two frontend + two back end). They support all major browsers (IE7+, Firefox, Chrome, Safari), mobile devices etc., they're really easy to use, no hassle at all when it comes to configuring things. The only thing that might be considered negative would be their pricing structure which seems quite expensive if you compare it to other platforms out there…