Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Esri ArcGIS - ArcGIS provides contextual tools for mapping and spatial reasoning so you can explore data & share location-based insights. ArcGIS is the heart of the Esri Geospatial Cloud. Try ArcGIS for free with 21-day trial.
Toby for Teams - Better bookmarks, now with collaboration baked in 🔖
Maptitude - Maptitude is a mapping software that is fitted with GIS features that avail maps and other forms of data regarding the surrounding geographical areas. Read more about Maptitude.
Planyway - Visual project management for Jira and Trello: manage resources, build project roadmaps, use time tracking.
QGIS - QGIS is a desktop geographic information system, or GIS.