Builditapp.com is an older site which the owner abandoned a few years ago. Because of this, some features don’t work, for example when subscribing to the premium version, you won’t be able to unsubscribe from it. There are many users complaining about this on the official Build It Discord Server.
Buildguides.net has a comprehensive layer-by-layer 3D viewer with useful features such as the ‘Measure Mode’. Blueprints can be viewed from all angles and you can build in your own pace.
In conclusion, while Builditapp.com can work well, Buildguides.net is a very good alternative with easy-to-follow instructions and helpful tools for building your dream Minecraft world.
