Seven Lakes — iOS Oil Well Management App

• Client: Seven Lakes Technologies
• Category: Enterprise · Oil & Gas
• Timeline: 8+ months
• Stack: iOS Objective-C · Swift · Core Data · Firebase · Xcode Instruments

About Seven Lakes Technologies

Seven Lakes Technologies built cloud and mobile software for upstream oil and gas operators, headquartered in Westlake Village, California. Its best-known product was the Field Data Gathering (FDG) mobile app, which lease operators use in the field to record well, tank and equipment data, often with no connectivity. The company reported more than 6,000 users across 50 clients, and W Energy Software acquired it in May 2022.

The challenge

FDG had to work reliably on remote well sites, but its iOS codebase had aged:

• Legacy Objective-C. Growing technical debt made changes slow and risky.
• Many client variants. Separate client-specific versions of the app all had to be maintained.
• Crash-prone code. There was no automated testing to catch problems before release.
• No shared architecture. Each variant had drifted, multiplying the cost of every fix.

What Appmetry built

Appmetry maintained and modernised the FDG iOS app:

• Objective-C to Swift migration onto modern architecture patterns.
• One unified app serving multiple client variants instead of separate builds.
• Offline-first data with Core Data, auto-sync and caching, so field data is captured even without a signal.
• Field workflows for well, tank and equipment data, EH&S tracking and chemical management, geo-location tagging and run ticket images.
• Quality tooling. Crash-free, testable code verified with Xcode Instruments, with Firebase and GitHub CI integration.

How we worked

The engagement ran for more than 8 months alongside Seven Lakes' engineering team, migrating the codebase while the app stayed in use by field crews.

The outcome

Seven Lakes moved from a legacy Objective-C codebase with multiple variants to a single, crash-free Swift app. Their engineering team said it gave them a stable, testable foundation to build on.

What this shows

Enterprise field apps carry years of client-specific changes. Consolidating variants during a language migration removes the duplicated maintenance cost, not just the old language. See how we handle enterprise transformation and mobile app development.

Sources for client background: W Energy Software acquires Seven Lakes Technologies, Oil IT Journal on Seven Lakes.

What our users say

"Appmetry delivered our entire platform ahead of schedule—flawless execution and real partnership."

Appmetry modernised our iOS codebase from Objective-C to Swift, unified our client variants into one app, and gave us a stable, testable foundation we can build on.

Seven Lakes Team

Engineering Team, Seven Lakes Technologies