Disable the iOS home button for the first app launched. Restart device to kick into effect after installing.

AppLock.mobileconfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>PayloadContent</key>
    <array>
        <dict>
            <key>PayloadDescription</key>
            <string>Disables the home button.</string>
            <key>PayloadDisplayName</key>
            <string>App Home Button Lock</string>
            <key>PayloadIdentifier</key>
            <string>nl.kluivers.joris.AppLock</string>
            <key>PayloadOrganization</key>
            <string>Joris Kluivers</string>
            <key>PayloadType</key>
            <string>com.apple.defaults.managed</string>
            <key>PayloadUUID</key>
            <string>B2D02E2D-BAC5-431B-8A29-4B91F71C9FC1</string>
            <key>PayloadVersion</key>
            <integer>1</integer>
            <key>PayloadContent</key>
            <array>
                <dict>
                    <key>DefaultsDomainName</key>
                    <string>com.apple.springboard</string>
                    <key>DefaultsData</key>
                    <dict>
                    <key>SBStoreDemoAppLock</key>
                    <true/>
                    </dict>
                </dict>
            </array>
        </dict>
    </array>
    <key>PayloadDescription</key>
    <string>Disables the Home Button</string>
    <key>PayloadDisplayName</key>
    <string>App Home Button Lock</string>
    <key>PayloadIdentifier</key>
    <string>nl.kluivers.joris.AppLock</string>
    <key>PayloadOrganization</key>
    <string>Joris Kluivers</string>
    <key>PayloadType</key>
    <string>Configuration</string>
    <key>PayloadUUID</key>
    <string>614D1FE3-F80D-4643-AF6B-D10C4CC8737A</string>
    <key>PayloadVersion</key>
    <integer>1</integer>
</dict>
</plist>