The development app is a very convenient bare bones version of the engine that allows you to push content to it over wifi. You install the development app on your device(s), start the app and then select the device as a build target from the editor.
Signing the development app (iOS)
Currently, at least one team member needs to run macOS and act as signer. The signer needs a code signing identity certificate installed on his/her computer. The signer also needs a mobile provisioning profile on his/her computer. (Note that the auto generated free provisioning profile Xcode can generate is only valid for one device)
To upload a signed development app to the Defold Dashboard, the following steps are required:
In the editor, select Project ▸ Sign iOS App…
Select your code signing identity.
Browse for your mobile provisioning file.
Press the Sign button.
The Defold dev app is uploaded to the project page on the Dashboard.
Each project member can now:
Browse to the Dashboard from their iOS device.
Open the project page from the list of projects.
Click the link Install the Defold App, which can be found below the Members section.
Installing the development dmengine (Android)
A stand-alone version of the Defold engine is available as a ready made .apk file that you can install on a device and use for iterative development wirelessly.
Make sure the your device UDID is included in the mobile provisioning that was used for signing the app.
Your device does not appear in the Targets menu
Make sure that your device is connected to the same wifi network as your computer.
The game does not start with a message about mis-matching versions
This happens when you have upgraded the editor to the latest version. On iOS you need to sign the app again (Project ▸ Sign iOS App…) which creates a new dev app from the current engine version. Then download the new app from the dashboard onto your device. On Android you will need to download a new dmengine.apk and install it on your device.