I preferred the German project Vreo.io. They are doing native in-game advertising and going to create marketplace for developers and advertisers. Developers of small games can attract investments and create high-quality products, for advertisers this project will be useful due to the expansion of advertising opportunities and selected target audience, and gamers will be able to receive quality products cheaper, besides they also receive income from the ads they watched, without interrupting the gameplay.
When I opened the website I couldn't find information about their roadmap, history, only 4 team members... Doesn't look very attractive. When I compare this website and Welltrado.io it's like day and night. Of course there is plenty of space to improve.