Google says it's been fighting hard against malicious developers and their bad apps. 

The search giant on Wednesday said the Google Play Store now scans more than 50 billion apps on users' devices every day in order to identify and stop bad apps, according to a post on the Android Developers Blog.

The Play Store rejected at least 55 percent more app submissions in 2018 than in 2017, according to the blog. Google didn't immediately respond to a request for how many apps were rejected in 2018. But for reference, the company removed over 700,000 apps in 2017.

Google said the company required third-party app developers to be transparent about how their app's collected and used sensitive user data. The search giant rejected or removed tens of thousands of apps last year because they didn't comply with this rule.

The search giant has found that 80 percent of malicious developers are repeat offenders and sometimes they work in a network. Google has employed machine learning and human reviewers to block their apps from being published.

"We know bad actors will continue to try to evade our systems by changing their tactics and cloaking bad behaviors," wrote Andrew Ahn, product manager of Google Play, in the blog post. "We will continue to enhance our capabilities to counter such adversarial behavior, and work relentlessly to provide our users with a secure and safe app store."