As detailed in a site update, since being founded by PickASO in 2017, hundreds of companies have used the ASO tool and boasted over 35,000 users.
Through the acquisition, TheTool customers will get access to further data and a wider feature set.
"App Radar and TheTool have a shared vision to ease the app marketing processes," wrote TheTool and PickASO CEO Daniel Peris.
"Therefore, I'm really pleased that through App Radar, our customers will get access to a wider feature set and more market data. From today onwards, our customers can benefit from one comprehensive tool with app store marketing analytics, research and market insights.
In one tool, users will get access to marketing analytics as well as research and market insights.
"Our goal is to become a one-stop-shop for app marketing products, and TheTool's range of market insights is an important piece of this puzzle," said App Radar COO Silvio Peruci.
"We plan to build on this achievement by further expanding our reach in Europe – particularly the UK and Germany – and doubling down on product development."