Mobile Apps (iOS and Android) where principals are able to find substitutions for absences of staff (teachers). The Apps should be very simple. Potential replacement teachers/substituts must be able to register with their profile/qualifications/photo/availability etc. Principals must be able to select and get in touch with suitable substitutes quickly. The profiles should be designed like cards (eg tinder) and a green dot for the "online status" of a candidate would be nice, principals can swipe through and connect with persons.