TdhGIS is described as 'Vector Based Spatial Analysis' and is an app in the Photos & Graphics category. There are more than 25 alternatives to TdhGIS for a variety of platforms, including Windows, Online / Web-based, Linux, Mac and Android. The best alternative is QGIS, which is both free and Open Source. Other great apps like TdhGIS are OpenLayers (Free, Open Source), PostGIS (Free, Open Source), GRASS GIS (Free, Open Source) and ArcGIS (Paid).
Professional desktop GIS supporting most ArcGIS (and other) data formats, enterprise spatial databases, 5,000 pre-defined coordinate systems, and built-in scripting IDE for customization and feature extensions.
GeoSheets is a free add-on for Google Spreadsheets that makes it simple to do lightweight GIS tasks like geocoding, address normalization, distance calculations and creating customized and embeddable maps.
Azimap is a web GIS developed on open source principles and offers GI professionals with the tools to visualise, analyse and share their spatial data on the web. Azimap provides customers with desktop capabilities on the web.
MapViewer is an affordable mapping and spatial analysis tool that allows you to easily produce publication-quality thematic maps. Precisely display your data distribution with the most intuitive functions and features.
vMAP Portal is a web GIS which provides data visualization, analysis, route calculation, reporting with an easy-to-use interface, central rights & roles, and can be easily integrated with other tools like BI, CRM etc. without much coding and setups.