Running a homelab there are quite a few tools which are useful for managing the servers and environment. This list won't be for everyone, however there may be some tools which you might find useful.
Note: Not all these apps are free.
Alfred Camera - https://alfred.camera/
CCTV isn't cheap and if you want to keep an eye on the physical in your server room or homelab then have a look at Alfred Camera. Setup a camera system by recycling those old android phones you've got lying around in draws.
Google Analytics - https://analytics.google.com/analytics/
The primary use is seeing how many people hit your blog or webpage, however more and more systems are including Analytics metrics for tracking application usage.
Authy - https://authy.com/
Its fair to say there are plenty of options for 2FA apps around because so many services support it. Authy is great and able to sync across multiple devices.
Bundled Notes - https://bundlednotes.com/bundles
I'm always looking for somewhere to keep notes and for a while was using Google Keep, then Standard Notes. I've recently moved over to Bundled notes which has apps and a web interface. Its the "bundling" of notes of a certain type and having them as notes, todo lists of a simple kanban board within Bundles I personally appreciate.
Fast - https://fast.com
Speed test tools are helpful and there are plenty around. Fast.com is simple, does what it says and has usually been quite accurate for me.
Flutterhole - https://www.flutterx.com/flutterhole-for-pi-hole
Theres no doubt that Pi-Hole is with out a doubt the easiers way to manage your DNS. Being able to do this from within an App just makes things a bit more portable and easier to manage.
IFTTT - https://ifttt.com
Not the darling it once was due to charging for more of the service. I find IFTTT highly useful for home automation tasks.
This is basically Portainer for Android and it works really well. At the time of writing its still in beta, however even at this stage i'm able to manage the Docker clusters I have and see whats running whats not from the mobile.
mikrotik - https://mikrotik.com/
I'm a huge fan of the Mikrotik hardware the routerOS and the speed they provide me for the size. I've included this here because they have a really good Android App too for configuring the router.
OpenConnect - https://www.infradead.org/openconnect/
I've included openconnect because the number of times i've worked at a location which uses Cisco VPN's and Anyconnect has got me out of a hole remote access wise while i'm out and about.
Proxmox virtual environment -https://www.proxmox.com/en/
From a virtualisation point of view either on a home lab or a small business Proxmox for me is the goto environment. The ease of use, web based interface, clustering, backups, storage support all out of the box for free. All sat on top of a familiar debian based core is huely appealing. This App just adds to this feeling for worth from the product.
Chrome Remote Desktop - https://remotedesktop.google.com/
As a big user of ChromeOS and Android I've found this useful for quick easy access to laptops running Windows or OSX. Its simple to setup, fast and locked to LAN Access.
Remote PC - https://www.remotepc.com/
An iDrive project which offers remote access to GUI based desktops or Servers over the internet using this secure client. I've found that even over the most low latency connections this service still performs really well. Its an alternative to services like TeamViewer which is well presented and easy to use.
Rocket Chat - https://rocket.chat/
I've spent a long time over the last year looking at options for team collaboration and have to say its Rocket Chat which suits my needs each time. Its quick to get running with Docker and the out of the box support for OAuth or JitsiMeet (cloud or self hosted) in an E2E encrypted environment.
Termius - https://termius.com/
However you're doing SSH today, stop it and do it with Termis a cross platform Gui for SSH which works perfectly. Keys, sites, groups its all there and its cloud sync (encrypted) feature is awesome if you run multiple devices.
Twingate - https://www.twingate.com/
If you run a VPN back to a home lab or even if you want a seperate support VPN setup. Twingate offers zero trust style remote access to your network. using a hybrid mix of cloud and locally hosted docker container the security is high, the setup is simple and the support team are great. Its also quicker than OpenVPN..
Its becoming easier and easier to pull away from a standard Windows/Mac/Linux desktop and manage your systems