There are numerous ways to visualize and analyze campaign fundraising, such as OpenSecrets. But there are comparatively fewer ways to analyze spending by political committees. Spending data is very helpful, though - it can help illuminate a committee’s activities, and thereby give opponents a window into that committee’s strategies. One example of a spend tracker is 527 Tracker, which specifically tracks the spending of federal Super PACs and cross-references it with commercial data sets like TV spending; Stephen Aaron discussed the project on Business of Politics in Oct 2022. While this project is useful in its own right, there are many extensions possible - for example, analyzing spending in state-level races.
Credit for this idea due to Davis Manoushagian.