> For the complete documentation index, see [llms.txt](https://en.docs.monaca.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://en.docs.monaca.io/products_guide/debugger/custom-build-debugger-for-ios.md). # Custom Build Debugger for iOS Monaca Debugger is an application to optimize the testing of apps. With Monaca Debugger, you can instantly check the app's operation on the actual device just by saving the source code. No need to build the app or install it on the device to check its operation. ## Instructions for Use ### 1. Prerequisites You need the following certificates to create a custom build debugger. Refer to [iOS Build Prerequisites](/build-app/build-for-ios.md) to get the required materials, which are the same as those needed for an iOS Debug build. * Private Key * Development Certificate * Development Provisioning Profile ### 2. Build an App Follow the steps below to build the debugger and install it on the physical device. 1. Log into Monaca Cloud IDE and open the project you want to debug. 2. Select Build > iOS App Build from the IDE menu. 3. Select Custom Build Debugger, then click Start Build. 4. Once the build is complete, the built app can be installed to the device using a QR code, or downloaded to a PC as a file.