David Dev

David AI App builder, ex Microsoft, Master of Computer Science

[Alex Nguyen @alexcooldev]

AI agents are great, but when I look at the bills, it almost feels like I’m hiring a senior developer. Since I’m currently managing many apps and internal tools, my monthly AI credit costs can reach $3K–$4K. 🫠

[Alex Nguyen @alexcooldev]

I’m back to building apps I genuinely enjoy, instead of only building apps designed to go viral.

To be honest, I’ve already built three simple, single-feature apps that generate revenue surprisingly easily but I’m keeping them in stealth mode for now. I’ll share them once I reach #1 in the market, lol.

Back to this project: Fable 5 was banned, but that’s fine. Opus 4.8 still works really well.

A quick reintroduction: I’m building a gamified workout and gym-tracking app. This market is already crowded, but none of the existing apps truly excite me, so I decided to build one specifically for myself with polished UI/UX and a proper gamification system.

Powered by Opus 4.8, Rork, and Cursor.

[Alex Nguyen @alexcooldev]

https://t.co/bVG4MMr6T6

[Alex Nguyen @alexcooldev]

I’m getting back to the challenge of building and marketing B2C mobile apps, while also launching a SaaS this summer.

Summer is when I have the most free time because my EdTech apps aren’t getting many new users, and existing users don’t require much support.

It’s the best time to build something new. 💪

[Alex Nguyen @alexcooldev]

Claude Fable is everywhere now. TikTok, IG, and now even growing on X. 😌

But with X, let it support you don’t let it generate your stories for you. Tell your own story.

[Alex Nguyen @alexcooldev]

And Fable 5 is also available on Rork. I’m about to enter full buildmaxxing mode. 💪

[Alex Nguyen @alexcooldev]

Your next users may not come from Google.

They may come from ChatGPT or any LLM.

I think LLM traffic is becoming the new SEO.

People around me are slowly changing how they search.

They don’t Google first anymore.

They ask ChatGPT.
They ask Claude.
They ask Perplexity.
They ask AI.
Even I do the same now.
So in 2026, if you’re building a product, don’t only think about TikTok, Instagram, or Google SEO.

Start asking yourself:
“How do I make AI recommend my product?”

Because the next big marketing channel might not be social media.

It might be AI search. 😌

[Alex Nguyen @alexcooldev]

Everyone wants to automate TikTok.

But automation should come AFTER you find a winning format.

Especially if you’re targeting the US with VPN/proxy.

My rule:

Test manually → find repeatable views → break down why it works → turn it into a template → automate the boring parts.

Automation won’t fix a bad format.

It only scales what already works.

[Alex Nguyen @alexcooldev]

https://t.co/TghRMA8H3C

[Alex Nguyen @alexcooldev]

Paid ads are great for scaling. If you’re profitable or can afford to take a loss, then it’s fine because it requires less effort.

But organic gives you a much higher profit margin, even though it takes a lot more work.

So yeah, it’s fair. 😌

[Alex Nguyen @alexcooldev]

I think in just a little more time, we won’t even be able to tell what’s AI and what’s human anymore. UGC creators are cooked 🥴

[Alex Nguyen @alexcooldev]

Honestly, this guy is really damaging the image of foreign tourists in Vietnam.

I’ve been seeing a lot of TikTok and YouTube channels in Vietnam covering this incident, and many Vietnamese people are genuinely outraged.

The sad part is, behavior like this doesn’t just affect him, it also creates a bad impression of other foreign tourists who actually respect the country, the culture, and the people here. 🥴

[Alex Nguyen @alexcooldev]

I just realized that quite a few of my followers are from the US, so I want to add a quick note:

All of these phones use VPN/proxy to target US users because I’m based in Vietnam.

But if you’re already in the US, the best option is to use a SIM and cellular data for each phone to optimize your phone farm and avoid TikTok flagging it as spam.

[Alex Nguyen @alexcooldev]

A lot of people have asked how much I invested into this.

Cost-wise, when I first started the project, I only bought around 2 phones at about $150 each to start creating content.

I only scaled up after I saw that my product had reached PMF.

After almost 2 years, I’ve scaled to around 20+ phones, which probably cost around $3k+ in total.

For VPN/proxy costs, it’s around $49/year, and I’m currently using 4 different ones, so that’s roughly $200/year.

And the total revenue I’ve generated over nearly 2 years across all my apps is around $300k+ (with the first few months generating almost low revenue)

[Alex Nguyen @alexcooldev]

https://t.co/Nei8HaZWLI

[Alex Nguyen @alexcooldev]

I don’t think AI “doesn’t work.”

AI that feels fake doesn’t work.

This app is getting ~90k downloads/month and doing $35k+/month mostly from viral AI clips.

And from my experience, almost every “revenue estimate” tool for apps is wrong when it comes to organic traffic. Usually the real revenue is 1.5x–4x higher.

I’ve already started using Arcads to build workflows for AI transformation videos for my weight loss app.

The workflow is honestly simple:

> Generate avatars with GPT Images 2.0 using JSON prompts
> Download viral TikTok transformation videos
> Use Kling Motion Control
> Recreate the same style with a different influencer
People underestimate how far AI UGC has already gone.

[Alex Nguyen @alexcooldev]

Hi @cursor_ai team, when I opened the old version of Cursor, it told me to download the new version for a better experience. But after downloading the new version, I can’t install it. Help me. 👋

[Alex Nguyen @alexcooldev]

https://t.co/vos9LHOq8v

[Alex Nguyen @alexcooldev]

https://t.co/I4LMeR2DxK

[Alex Nguyen @alexcooldev]

At the same time as HRG in Da Nang, we also have Cursor Café in Da Nang during the same month. Da Nang is 🔥 now