KDE Connect - Integrate Android with the KDE Desktop
Type2phone - Type2Phone: Use your Mac as keyboard for iOS devices
Pushbullet - Pushbullet - Your devices working better together
Typeeto - Use Mac’s keyboard to type on iPad, iPhone, Android, etc.
mconnect - Vala/C implementation of KDE Connect
1keyboard - Type on your iPhone, iPad or AppleTV using your Mac keyboard