The Crew Chief app is one of those apps in sim racing that's considered by many as a must-have. We're part of those many. In its basic form, Crew Chief will talk to you, informing you of the gaps between cars, your fuel remaining, incidents on track, etc. From there, it can be configured to provide a lot more info and can even be accessed via voice control.
Very few apps can come close to providing this level of information while remaining totally free. LMU Race Engineer may be an alternative to Crew Chief, and we'll go through its key features in this article to determine if it's worth switching to.
LMU Race Engineer - Key Features
LMU Race Engineer has several features that make it a decent option instead of Crew or any other app that provides voice notifications and even on-screen overlays.
Race Dashboard
This is the main screen that you can use as an overlay on either your main screen or on a secondary display. It also has the option of linking to SimHub, which then means you can have it available on the screen of your steering wheel.

This screen gives you all of the main indicators you would expect, including tyre info, gaps to other cars, fuel, etc.
Messages and Voice Calls
This shows up on-screen with critical info warning you of potential issues with tyre wear, when to push or defend, if you've had a track limits violation, etc. Messages will also pop up as voice messages, Crew Chief-style.

Attack and defend modes, along with a qualifying hasdboard is also available. These modes also contain both visual and voice messages that are there to aid you during races and qualifying.

The qualifying dash gives you a screen that has the critical data you would need during qualifying, allowing you to focus on the session and not get distracted by unwanted info.
Final Thoughts
LMU Race Engineer is a free app for Le Mans Ultimate and features both visual and voice elements that can definitely help with race and qualifying sessions. It does not support any other sim as of the time of writing this article, and we can't find a roadmap for it to see if there are any plans to expand it in terms of additional features.
Another more important issue is the lack of pricing info. It is free right now, but there's no indication if the developer intends to keep it this way or move to a paid model.
It's still very early days for LMU Race Engineer, and we see that it has some potential, but the Crew Chief app is still the gold standard. Regardless, we like what this has to offer and suggest that you take it for a few laps and see for yourself.