Maptitude Online is the best alternative to the AppGeo GPV (General Purpose Viewer).
Maptitude Online provides all the resources you need to build and publish geospatial data, as well as unique features for developing and operating mobile web mapping apps and GIS online services on the Cloud. You can easily construct basic applications without scripting, utilizing an established framework and connecting it to your geographic information.
Maptitude supports an extensive list of file and data formats including those from Esri:
Learn more about Maptitude Share Maptitude Maps on the Web
Maptitude Online Sharing allows you to share the maps and reports that you create in Maptitude with people who don't have the desktop Maptitude software. The straight-forward publishing tools allow you to easily distribute your findings and results to those that need them within an organization and beyond.