fun iOS iPhone app

Fitbit is losing momentum

Why I am saying that?

I am the only active person among my “Fitbit friends”. So I assume it could means a few things:
1) All my friends stopped wearing Fitbit;
2) All my friends did not sync (or their Fitbit could not sync, which I admit is a real problem for Fitbit);
3) All my friends got Apple watch (or something nicer, good for them 🙂


The stock (NYSE:FIT) has been absolutely horrible YTD, or to be more exact since its IPO about 15 months ago. I am glad my trades worked out this year though 🙂


I am speculating one reason is Apple Watch is taking off. Although I tried to stay away from that $300+ “need to be charged daily, always on” gadget, it seems it’s the inevitable with the so called “series 2”. I feel the nike+ version with the swimming is the way to go. Now if I could offload a few items on ebay to make the $300 bucks…

advice and tips finance iOS

Discover Apple Pay 10% cash back until end of year

With $10000 as spending limit. The prerequisite: iPhone 6, 6+, 6s, 6s+; iOS 9; in store purchase, no giftcard.

Stores support Apple Pay

Here in St. Louis, Schnucks, Dierbergs, WalGreens, St. Louis Bread Co. (Panera Bread) all supports Apple Pay. Though on Sept. 17 I tried at Schnucks counter, it failed, note this is the 2nd day of Discover Apple Pay launch, so it could be a glitch. It worked on Panera Bread (Sept 18, 19). I will also try Trader Joe’s as I saw it’s coming soon from the Apple website.

Why iOS 9 for Apple Pay
It’s a bit more security. Previously one can add a card to Apple Pay just from the physical card. So basically if a card is stolen, technically it can still be added. Obviously the card issuer usually has fraud detection system in place to catch those. But iOS add a two factor authentication when adding a new card, which is definitely a great idea. We catch the problem earlier this way. A thief cannot add a stolen card as easily as it used to be.

Btw, I saw the fingerprint based authentication get popular as BoA app and other apps (e.g., Apple’s own iTunes connect) use that for authentication. Save some typing work and more security.

(Update 09-20-15) It appears Discover Apple Pay still does not work on local Schnucks store. It prompts “do you want cash back”, I said “No”, then the transaction got declined. Something at a miss at Schnucks or their payment processor. Because it does work at Panera (St. Louis) Bread since Sept 18. I guess one way to test it is to swipe Discover Card directly to see if it works 🙂

(Update 09-25-2015) Used Apple Pay with Discover at Subway for lunch today, it worked flawlessly.

(Update 09-27-2015) Worked in Trader Joe’s too.

(Update 11-07-2015) Discover Apple Pay works in Schnucks now. 

advice and tips iOS

How to fix iPhone 5 5s 6 6 plus speaker after dropping it to water

I made this mistake again. Last time I dropped my iPhone 4 into water, I tried this “put it in rice” strategy. This time I also this trick, but the speaker was not still working. Luckily I found this youtube video on the web, basically I used a cotton knob to clean up the headphone jack. It worked.

advice and tips finance iOS iPhone app

Small changes coming to collegeFund app

I was listening/reading two stories on the college debt (source: NPR) and the financial well beings of millennials (source: fortune/cnn), which lead to to add some new features to the collegeFund app. The app was essentially a college savings (529 plan) and I did not thought too much of this college debt problem at the time the app was conceived 3.5 years ago. At the time I opened 529 plan for my daughter, and started put some money into it.

A lot has changed in my personal finance and to the economy in general. Now I felt for a lot of people, college debt is like a mortgage, it’s just something they have to bear with, and manage while go on with their lives. Btw, I saw another good resource for college debt here.

I just updated the app, submitted to the app store, it’s under review now. Here is the screenshot. Let me know if you have any questions. Email me at minjie dot xu AT gmail dot com.


(Update 05-10-2014) I made couple more updates to fix bugs I introduced when adding this “debt free” tab/screen. It’s mostly settled now. I am thinking other enhancements, along with myNestEgg app.


UITableView update problem

It appears the UITableView cells created via storyboard is not updating correctly, say, if we want to add or delete a row. It only update once. The workaround in this case is creating the rows programmatically (instead of static tags from storyboard).

Similarly, I recall the JSF Richfaces paging problem when add/delete a row which results in the number of pages change.

I am guessing one possible cause of this type of problem is the update process runs into deadlock.


Another simple data grid example on iOS

I came across this example in Jan 2012 (almost 2 years ago :-). A lot has changed in iOS landscape, but the author did a good job designing the application, I think.
Displaying Tabular Data on iPhones (Tom Thompson, overview of UITableView)

Making Two-Way Tables in iOS

(a two dimensional table, with text field as input)


The modified GMGridViewDemo

I added the 3rd tab has the excel like data table, the screen shot shown below. I can provide the source code if needed. Just email me at minjie dot xu AT gmail dot com

spreadsheet on iPad


Announcing iDataGrid ~ a place dedicated to data grid table on iOS

A little over a year ago, I started working full time as iOS developer for a mining company. One of the first projects is create spreadsheet like application on iPad. At that time there is no UICollectionView, and I found GMGridView to be interesting. I did look at an existing product called iOS Data Grid Table but there are two limitations which prevents me from using it: 1) It displays the values only (read only); 2) Perhaps more important, at that time I don’t recall it includes source code. So I ends up creating my own spreadsheet like tables based on GMGridView. I also read the nice work done by Tom Thompson. Of course that time my knowledge on UITextField (and UITableView for that matter) is not very good, and I did not understand all good work he did. I did used the UIPicker in my project, as it helps the user input data in many cases (simplify/ease input, reduce validation), I believe I borrow some idea from RayWenderlich’s tutorial too (UIPopupController and UIPicker).

A year and half later, when I took another look at this thing, I found at least four new things which are interesting, the shinobi controls (commerical), the MDSpeadView (looks like read only, github, open source), nucliOS (by Infragistics, commercial) and UICollectionView (Apple iOS native, tutorial by