Linphone App Customization

We need to customize linphone's windows/macOS/iOS/android apps with regular PBX features, sms,sip

Presence,BLF,etc.
Needs to be customize with our company logo/colors.
Change colors and logos to match our theme.
Sleek and professional design.
Login screen to accept username and password or scan QR code
Incoming and outgoing calls.
Call Transfer (Blind and assisted transfer)
Hold Call
Transfer Call
Attended Transfer Call
End Call
Conference Call (merge the calls)
Video calls
Presence and IM features
Call history
Smart contact list, with address book synchronization for smartphones
Audio/video conference calls and scheduled meetings
Call transfer and multi-call management (pause and resume)
One-to-one and multi-participant conversations
Intuitive message delivery status (IMDN)
SMS/chat with Message Syncing for all devices (Meaning sms/chats will be synced, so users can see the conversations).
Recordings on server (We have APIs to do that and check if user is allowed).
BLF
Voicemail

Plus a few additional features.

The ideal developer for this project should have experience in:
- Mobile app development, specifically on iOS and Android platforms
- Proficiency with Linphone or similar VoIP applications
- UI/UX design to make the necessary interface changes
- Integrating applications with third-party services
- Meeting tight deadlines

As I require this project to be completed ASAP, promptness is crucial. Please provide a timeline for completion in your bid.