What are the available security testing tools for Android and iOS apps? Mainly for a passive scan for known vulnerabilities.
Many passive scanners exist to give holistic views of both a device and services running on it. So, while running a scan against a device with the application running and its ports open will give you a little bit of info, likely it will lead to many rabbit holes that will eat additional time.
What I would do to start (as if that counts for something), is to set a proxy between your device and any services it communicates with externally, since most apps don't run things solely on the handset itself. Observe the traffic, and record it. Then use a tool such as BurpSuite or Zed Attack Proxy (ZAP) to fuzz the ingress/egress points on the application and its supporting services based on that recorded traffic.
This will still give you data on where weak points are, what external communications maybe don't communicate over HTTPS, and other things of that nature. Both Burp and ZAP have pre-existing fuzzing options to start with as well, which may be a good place to start. It also requires minimal setup or meddling with the devices themselves.
The majority of low hanging fruit issues for mobile applications are from their external communication, so this approach will cover much of that. Other approaches get more invasive to the device and will require you to interact with ADB and start doing a little bit of reverse engineering.
Hope that helps.
I don't specifically know any security testing tools for mobile, but I wouldn't rely on them because you won't learn security testing by only using tools. Try to manually test for security vulnerabilities. This won't be easy. First, try to understand the mobile architecture, not only the application. Then learn to use the debugging tools. For example, ADB on Android. Here are some resources that might help you: